Shared Broadband Light Source for PON Wavelength Precision
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wavelength-specific laser transmitters in passive optical networks (PONs) contribute significantly to system cost and complexity due to the need for precise alignment and maintenance of extra specific-wavelength lasers, while tunable colorless lasers require stringent temperature control and are costly.
Innovation Solution
Implementing a shared broadband light source (BLS) to feed seed light to a plurality of injection locked laser transmitters across multiple PONs, reducing the number of BLSs and improving power usage by using a broadband light signal filtered into narrowband signals for each PON, enabling coherent light transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If wavelength-specific laser transmitters are used in PONs, then transmission precision and wavelength stability are improved, but system cost and complexity increase due to precise alignment requirements and maintenance of extra specific-wavelength lasers
Solution Approach 1:
The patent combines multiple wavelength-specific laser transmitters into a single broadband light source that serves multiple PONs. Instead of each PON having its own dedicated wavelength-specific laser, a single BLS generates multiple wavelengths that are distributed to multiple PONs, reducing the total number of laser transmitters while maintaining wavelength precision through the injection-locked laser mechanism
Solution Approach 2:
The broadband light source is designed to serve multiple functions: it generates multiple wavelengths simultaneously, each wavelength can be assigned to different PONs, and the same BLS can support both upstream and downstream transmissions. This multi-functional approach replaces the need for dedicated wavelength-specific lasers for each PON
2Adaptability or versatility
If tunable colorless lasers are used, then wavelength flexibility is improved, but system cost increases and temperature control requirements become more stringent
Solution Approach 1:
The broadband light source is segmented into multiple discrete wavelength components that can be independently assigned to different PONs. Each wavelength channel is separated and distributed independently, allowing flexible wavelength assignment without requiring complex temperature control of tunable lasers
Solution Approach 2:
The patent introduces an intermediary mechanism (the broadband light source with optical filtering and injection-locked lasers) that provides wavelength flexibility without requiring directly tunable lasers. The BLS acts as a mediator that converts a single broadband source into multiple stable wavelength channels through passive optical components
3Reliability
If multiple broadband light sources are used for multiple PONs, then each PON has dedicated seed light, but system cost and power consumption increase
Solution Approach 1:
Multiple dedicated broadband light sources are merged into a single shared BLS that serves multiple PONs. The single BLS generates all necessary wavelength channels that are then distributed to multiple PONs through optical splitting and injection-locked laser transmitters, reducing total power consumption while maintaining seed light availability
Solution Approach 2:
The system enables self-service by allowing the single BLS to automatically generate and distribute all necessary wavelength channels to multiple PONs without requiring external intervention or additional light sources. The injection-locked laser transmitters at each ONU self-generate stable wavelengths using the seeded light from the shared BLS
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration reduces system complexity and cost by minimizing the number of BLSs, improves power efficiency, and maintains adequate transmission characteristics for PONs, while also enhancing reliability by distributing seed light signals across multiple PONs.
Implementation Method 1
using a broadband light signal filtered into narrowband signals for each PON
Implementation Method 2
injection locked laser transmitters
Data Source
AI summary
An apparatus comprising a first optical transmitter configured to couple to a second optical transmitter, a first optical receiver, and a seed light source, wherein the first optical transmitter and the first optical receiver are part of a first passive optical network (PON) and the second optical transmitter and a second optical receiver are part of a second PON, and wherein at least one of the first optical transmitter and the second optical transmitter is an injection locked laser transmitter. Also disclosed is a method comprising feeding a seed light to a plurality of injection locked laser transmitters in a plurality of PONs using only one broadband light source (BLS), wherein each PON comprises an optical line terminal (OLT) transmitter and a plurality of optical network units (ONUs) transmitters.